Hyponatremia is one of the most common lab abnormalities seen in clinical practice. It has become widely accepted that hypothyroidism is a cause of euvolemic hyponatremia. The primary mechanism is thought to be due to impaired free water excretion and changes in sodium handling in the kidney. However, the clinical studies are conflicting and do not definitively confirm the association between hypothyroidism and hyponatremia. Therefore, if severe hyponatremia occurs in a patient without myxedema coma, other potential etiologies should be sought.

中文翻译：

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甲状腺功能减退症和低钠血症之间是否存在因果关系？

低钠血症是临床实践中最常见的实验室异常之一。人们普遍认为，甲状腺功能减退症是导致血容量正常的低钠血症的原因之一。其主要机制被认为是由于游离水排泄受损和肾脏钠处理能力的变化。然而，临床研究相互矛盾，并没有明确证实甲状腺功能减退症和低钠血症之间的关联。因此，如果没有粘液性水肿昏迷的患者发生严重低钠血症，则应寻找其他潜在的病因。